THE FIRST STUDY EXAMINES THE EFFECTIVENESS OF A PUBLICITY CAMPAIGN TO ENCOURAGE THE PUBLIC TO LOCK UNATTENDED VEHICLES AND SO REDUCE CAR CRIME. THE CAMPAIGN WAS CONDUCTED IN PLYMOUTH, ENGLAND, AND ENTAILED USE OF POSTERS AND HANDBILLS, TELEVISION AND RADIO SPOTS, NEWSPAPER ANNOUNCEMENTS, AND OTHER DEVICES TO INCREASE PUBLIC AWARENESS OF CAR THEFT THREATS. EFFECTIVENESS OF THE CAMPAIGN WAS GAUGED USING PATROL-OFFICER-COLLECTED DATA ON PERCENTAGES OF CARS OBSERVED TO BE LOCKED AND OFFICIAL RECORDS ON AUTO THEFT FOR THE STUDY PERIOD. THE RESULTS SHOW THAT THE CAMPAIGN DID NOT SUCCEED IN PERSUADING A GREATER PROPORTION OF DRIVERS TO LOCK THEIR CARS, NOR DID IT EFFECT A REDUCTION IN CAR CRIME. POLICE DETERMINED THAT LACK OF PUBLIC CONCERN MAY BE DUE TO DRIVERS' PERCEPTIONS THAT THE RISK AND THE CONSEQUENCES OF HAVING A CAR STOLEN ARE NOT SERIOUS. YOUNGER DRIVERS, IN PARTICULAR, PERCEIVE THAT MOST CAR THIEVES WOULD NOT BE DETERRED BY A LOCKED VEHICLE. THE SECOND STUDY EXAMINES THE EFFECTIVENESS OF TRUANCY PATROLS IN REDUCING CRIMES COMMITTED BY CHILDREN. IT INVOLVED A TIME SERIES STUDY OF TRUANCY INCIDENCE AND CRIME INDEXES BEFORE AND AFTER A PERIOD OF STEPPED-UP TRUANCY PATROLS. THERE WAS LITTLE CONVINCING EVIDENCE THAT THE PATROLS CUT CRIME AT TIMES WHEN CHILDREN SHOULD HAVE BEEN AT SCHOOL, AND NO IMPLICATIONS FOR LONGER-TERM PREVENTIVE EFFECTS OF THE PATROLS OR OTHER BENEFITS THAT MAY HAVE ACCRUED. TABULAR DATA, FOOTNOTES, AND REFERENCES ARE INCLUDED FOR EACH ARTICLE. FOR SEPARATE PAPERS, SEE NCJ 64358-59. (AUTHOR ABSTRACT MODIFIED--PRG)